https://bugs.kde.org/show_bug.cgi?id=517334
Bug ID: 517334
Summary: KDE System Monitor 6.6.2 shows 0% GPU usage for Intel
Arc A380 (ksystemstats wrong i915 event_source path)
Classification: Applications
Product: KSystemLog
Version First unspecified
Reported In:
Platform: Other
OS: Linux
Status: REPORTED
Severity: normal
Priority: NOR
Component: general
Assignee: [email protected]
Reporter: [email protected]
Target Milestone: ---
KDE System Monitor 6.6.2 shows 0% GPU usage for Intel Arc A380 (ksystemstats
wrong i915 event_source path)
### Product / Components
- Product: Plasma
- Component: `ksystemstats` / System Monitor GPU sensors
- Version: 6.6.2 (KDE neon User Edition, up to date)
### Description
On my system with an Intel Arc A380 (Sparkle) discrete GPU, KDE System Monitor
always shows **0% GPU utilization**, even under heavy load, while
`intel_gpu_top` and other tools report correct usage.
The Intel GPU appears to be working correctly in the kernel and userspace:
- `intel_gpu_top` shows live engine usage for `Intel Dg2 (Gen12) @
/dev/dri/card1`.
- `CAP_PERFMON` is set on `ksystemstats_intel_helper`.
- `perf_event_paranoid` is set to `2`.
However, `ksystemstats` logs an error about a missing event_source device
directory and never reports any GPU load.
### System information
Please edit these lines to match your system if needed:
- Distro: KDE neon User Edition (Ubuntu‑based, fully updated as of March 2026)
- Plasma: 6.6.2
- KDE Frameworks: (whatever System Settings → About shows)
- Qt: 6.x (from About)
- Session: Wayland
- CPU: Intel Core i7‑4930K (X79 platform)
- GPU: Intel Arc A380 (Sparkle) discrete card, using `i915` driver
- `/dev/dri`:
```bash
ls -l /dev/dri
total 0
drwxr-xr-x 2 root root 80 Mar 9 05:43 by-path
crw-rw----+ 1 root video 226, 1 Mar 9 05:43 card1
crw-rw----+ 1 root render 226, 128 Mar 9 05:43 renderD128
```
### Commands run / configuration
```bash
# Give Intel helper perfmon capability
sudo setcap 'CAP_PERFMON=+ep'
/usr/lib/x86_64-linux-gnu/libexec/ksystemstats_intel_helper
getcap /usr/lib/x86_64-linux-gnu/libexec/ksystemstats_intel_helper
# Output:
# /usr/lib/x86_64-linux-gnu/libexec/ksystemstats_intel_helper cap_perfmon=ep
# Relax perf security to allow GPU PMUs:
cat /proc/sys/kernel/perf_event_paranoid
# 2
```
`intel_gpu_top` works and shows live usage:
```bash
sudo intel_gpu_top
# Shows: Intel Dg2 (Gen12) @ /dev/dri/card1 with Render3D/Video/etc engines
```
`ksystemstats` is running:
```bash
ps aux | grep ksystemstats | head
# joechia+ 3214 1.1 0.0 338480 41752 ? Ssl 05:45 0:11
/usr/bin/ksystemstats
```
### Relevant journalctl logs
>From `journalctl -b | grep -i ksystemstats`:
```text
Mar 09 05:44:30 x79a380hexacorex12i7 dbus-daemon[1787]: [session uid=1000
pid=1787] Activating via systemd: service name='org.kde.ksystemstats1'
unit='plasma-ksystemstats.service' requested by ':1.57' (uid=1000 pid=2706
comm="/usr/bin/plasma-systemmonitor" label="unconfined")
Mar 09 05:44:30 x79a380hexacorex12i7 systemd[1769]: Starting
plasma-ksystemstats.service - Track hardware statistics...
Mar 09 05:44:30 x79a380hexacorex12i7 dbus-daemon[1787]: [session uid=1000
pid=1787] Successfully activated service 'org.kde.ksystemstats1'
Mar 09 05:44:30 x79a380hexacorex12i7 systemd[1769]: Started
plasma-ksystemstats.service - Track hardware statistics.
Mar 09 05:47:19 x79a380hexacorex12i7 ksystemstats[3214]: "Device directory
\"/sys/bus/event_source/devices/i9150000_04_00.0\" does not exist\n"
```
That last line looks like the root cause: `ksystemstats` is looking for an
`i915` perf event_source directory named `i9150000_04_00.0`, but on this system
there is only `card1` and `renderD128` under `/dev/dri`, and
`/sys/bus/event_source/devices/i9150000_04_00.0` really does not exist. As a
result, the Intel GPU plugin never finds a PMU and System Monitor’s GPU
utilization stays at 0%.
### Expected vs actual behavior
- **Expected**: System Monitor GPU sensors show non‑zero utilization for Intel
Arc (DG2) when the GPU is under load, similar to what `intel_gpu_top` reports.
- **Actual**: System Monitor shows 0% GPU usage at all times. `intel_gpu_top`
reports correct usage.
### Steps to reproduce
1. Boot KDE neon User Edition with Intel Arc A380 (DG2) as primary GPU, using
`i915` driver.
2. Install `intel-gpu-tools` and verify `sudo intel_gpu_top` shows live engine
usage.
3. Set:
```bash
sudo setcap 'CAP_PERFMON=+ep'
/usr/lib/x86_64-linux-gnu/libexec/ksystemstats_intel_helper
sudo sysctl kernel.perf_event_paranoid=2
```
4. Log out and back in (or reboot).
5. Open **System Monitor → Edit Page**, add a GPU utilization graph, and put
the GPU under load (game, benchmark, etc.).
6. Observe that GPU utilization remains 0% while `intel_gpu_top` shows non‑zero
usage.
7. Check `journalctl -b | grep -i ksystemstats` and see:
```text
Device directory "/sys/bus/event_source/devices/i9150000_04_00.0" does not
exist
```
### Request
Could `ksystemstats` be updated to:
- Discover the correct `i915`/Arc perf event_source device directory
dynamically on DG2/Arc (instead of hard‑coding `i9150000_04_00.0`), or
- Use the same mechanism as `intel_gpu_top` to locate the GPU PMUs?
If you need additional logs (full `inxi -Gxx`, `ls -R
/sys/bus/event_source/devices`, or a debug build), I’m happy to provide them.
***
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